This is a research study aimed at assessing the impact of oral contraceptive (OC) use on bone metabolism in women with hypothalamic amenorrhea (HA). A total of 76 women will be enrolled across all centers and we have been asked to enroll a minimum of 15 women with HA. HA is a condition of premenopausal women and is characterized by hypoestrogenism. Estrogen replacement therapy has been shown to slow bone resorption and improve cognitive function in postmenopausal women. This study aims to determine if OC's are helpful in slowing the bone resorption process in women with HA and to assess the impact of OC's on cognitive function. Biochemical and radiological measures of bone metabolism and strength will be ascertained as will cognitive function pre and post treatment.